This disclosure generally relates to exploration and production of hydrocarbons involving investigations of regions of an earth formation penetrated by a borehole. More specifically, the disclosure relates to a nested drill bit arrangement configurable for types of earth formation and drilling multiple borehole sizes.
Generally, boreholes are drilled in multiple different sections. For example, each section of the borehole decreases in diameter as the borehole progresses deeper in the earth formation. The progressively smaller diameter borehole sections are drilled by progressively smaller diameter drill bits. When a new section of borehole having a smaller diameter is needed, the previous drill bit is tripped out of the borehole, new casing is run downhole, and a new smaller diameter drill bit is run downhole to commence drilling the new section of borehole.